World's
Famous Lakes of Killarney

Central to Killarney
National Park are the world famous Lakes of Killarney, which
make up almost a quarter of the Park's area. The three lakes
are known as the Upper Lake, Muckross Lake (Middle Lake) and
Lough Leane (Lower Lake), and are joined at the 'meeting of
the waters', a popular area for visitors to the Park. It is
here that the Old Weir Bridge (thought to be over 400 years
old) can also be seen. From the meeting of the waters a narrow
channel known as the Long Range leads to the Upper Lake, which
is the smallest of the lakes but set in the most spectacular
location, in the heart of the rugged mountain scenery of the
upper Killarney Valley/Black Valley area. The sandstone and
blanket bog of the catchment area means that the Upper and Middle
Lakes are slightly acidic and low in nutrients (oligotrophic).
A fast run-off in the mountainous catchment also means that
in heavy rain the level of the entire Upper Lake can sometimes
rise by up to a meter in a matter of a few hours.

Muckross Lake
is the deepest of the lakes with a maximum depth of approximately
75 meters (250 feet) close to where the steeply sloping face
of Torc Mountain enters the lake. Both Muckross Lake and Lough
Leane lie astride the sandstone/limestone boundary, and the
presence of limestone means that both of these lakes are slightly
richer in natural nutrients than the Upper Lake. At lake level,
there are many caves in the limestone which are formed by the
dissolution effect of acidic waters on the exposed rock, especially
when combined with wave action. Nowhere are these caves more
marked than on the northern shore of Muckross Lake.

Lough Leane is
by far the largest of the three lakes, at approximately 19 km,
and is also the richest in nutrients. Organic pollution (particularly
phosphates from domestic and agricultural sources) entering
Lough Leane has led to a partial eutrophication of the lake
and several well publicised algal blooms have occurred in recent
times. Although they can look unsightly, these blooms do not,
as yet, appear to have had a severe effect on the natural life
of the lake. If enrichment continues unabated however, the lake
ecosystem may be altered to the extent that the character of
the lake will permanently change, and a broadly-based review
of land use within the entire catchment is therefore currently
in progress in an effort to address the issue. A community-based
initiative aimed at minimising the use of domestic and agricultural
phosphates is also currently in progress, and it is hoped that
a sustained effort will improve the water quality in years to
come.

There are many
Brown Trout in the lakes, in addition to an annual run of Salmon.
Unusual fish species include the Arctic Char (usually found
much further north, and thought to be a relict species left
behind in Killarney after the last ice age) and the Killarney
Shad (a land locked form of the Thwaite Shad unique to the Lakes
of Killarney). The discovery of a small number of Roach a number
of years ago, a potentially explosive breeder that was presumably
introduced accidentally by visiting anglers, led to fears that
the trout may be displaced in some parts of the lake however
this fear has not materialised and Roach have not been recorded
for several years.

Several different
tours by boat are available for visitors to the Park, from short
trips to Inisfallen Island, to the full passage of the lake
system from Lough Leane to the top of the Upper Lake.